Bushkiller, an aggressive perennial vine native to Southeast Asia, has invaded several sites in Alabama, North Carolina, Texas, Louisiana, and Mississippi. Bushkiller has only recently been discovered in North Carolina. The potential economic and environmental consequences associated with established exotic invasive perennial vines and the lack of published control measures for bushkiller prompted research to be conducted at North Carolina State University that may be used in an early-detection rapid-response program. Field and greenhouse studies were conducted to determine bushkiller response to selected foliar-applied herbicides. Field study 1 evaluated efficacy of glyphosate, triclopyr, triclopyr plus 2,4-D, triclopyr plus aminopyralid, and triclopyr plus glyphosate applied postemergence to bushkiller. No control was evident from any treatment at 10 mo after application. In a separate experiment, aminocyclopyrachlor, imazapyr, metsulfuron, sulfometuron, and sulfometuron plus metsulfuron were applied postemergence to bushkiller. Control with aminocyclopyrachlor, imazapyr, sulfometuron, and sulfometuron plus metsulfuron was 88 to 99% at 10 mo after application. Each treatment was also applied to bushkiller in a greenhouse trial. Aminocyclopyrachlor and triclopyr-containing treatments generally resulted in the greatest control, lowest dry weights, and shortest vine lengths among the treatments. These results indicate that several herbicides may be employed initially in an early-detection, rapid-response program for bushkiller. Additional research is needed to determine how effective these herbicides would be in multiple-season treatments that may be required at well established bushkiller infestation sites.
Nomenclature: 2,4-D; aminocyclopyrachlor, 6-amino-5-chloro-2-cyclopropyl-4-pyrimidinecarboxylic acid; aminopyralid; glyphosate; imazapyr; metsulfuron; sulfometuron; triclopyr; bushkiller, Cayratia japonica (Thunb.) Gagnep
Interpretive summary: Bushkiller is an exotic invasive perennial vine in the Vitaceae family that has been documented in Texas, Louisiana, Mississippi, Alabama, and North Carolina. In North Carolina, bushkiller has recently been listed as a Class B Noxious Weed by the North Carolina Department of Agriculture. Bushkiller aggressively overtops neighboring vegetation, making it problematic ecologically and economically. An extensive literature review provided no guidelines for control of bushkiller. Therefore, selected herbicides were evaluated to initiate development of bushkiller control guidelines. Further studies are needed to document the effects of multiple-season applications of these herbicides. Our results from one season of treatments indicated that multiple-season applications of a selected herbicide will be necessary for eradication of existing bushkiller infestations.